Speciation of nitrogen -: [N3-] and [N22-] -: in binary compounds

The nitrogen content of the binary compounds SrN = Sr-4[N](2)[N-2], Sr[N-2] and Ba[N-2] (prepared by high-pressure syntheses) was determined analytically by using the carrier gas hot extraction method. For handling of the air- and moisture-sensitive samples, a transfer chamber was constructed to protect the compounds against decomposition before being analyzed. Additionally, it was necessary to develop a method allowing controlled and variable heating of the electrode furnace to get analytical results with high precision and accuracy. By means of a suitable temperature program it was possible not only to verify the existence but also to quantify the two different nitrogen species ([N3-] and [N-2(2-)]), and thus confirm the results of recent neutron diffraction studies.